The main function of this module is to accept interactive input.
You specify the type of inputs allowed, a prompt, help text and
defaults and it will deal with the user interface, (and the user!),
by displaying the prompt, showing the default, and checking to be
sure that the response is one of the legal choices.  Additional
"types" that could be added would be a phone type, a social secu-
rity type, a generic numeric pattern type...
